Liquid Penetrant Inspection (DYE)

Liquid Penetrant Inspection method works by the application of a dye to the surface of a part. The dye will use a capillary action to penetrate into surface discontinuities. After the application and removal/cleaning of the dye from the surface a developer will be applied. The developer will draw penetrated dye to the surface leaving a contrasting indication. Liquid Penetrant Inspection is used solely for the purpose of detecting surface discontinuities.

Advantages
  • Can be used on a wide variety of materials and parts
  • Extremely portable
  • Simple and fast
  • Can easily detect discontinuities as small as 4 µin or 0.1 µm
  • Economical
  • Detects all surface discontinuities in one operation
  • Indications are produced directly on surface of the part providing a visual image of the discontinuity
  • Can be used on ferrous & non-ferrous materials
Limitations
  • Only able to detect surface discontinuities
  • Cannot be used on rough, rusty or porous materials
  • Materials must be cleaned thoroughly and free of grease or paint